This section provides background information related to the present disclosure which is not necessarily prior art.
Seat assemblies such as those used in conjunction with vehicles typically include an adjustment mechanism disposed at a junction of a seatback and a seat bottom of the seat assembly. Locating the adjustment mechanism at a junction of the seatback and the seat bottom provides for selective adjustment of the seatback relative to the seat bottom. Namely, conventional adjustment mechanisms are typically movable between a locked state, restricting movement of the seatback relative to the seat bottom, and an unlocked state permitting movement of the seatback relative to the seat bottom.
A round-recliner mechanism is a type of adjustment mechanism and typically includes a gear plate associated with one of the seat bottom and the seatback, a guide plate associated with the other of the seat bottom and the seatback, a locking mechanism disposed between and supported by the gear plate and the guide plate, and an actuation mechanism that selectively moves the locking mechanism between a locked state and an unlocked state. When the locking mechanism is in the locked state, relative rotation between the gear plate and the guide plate is restricted and, as a result, rotation of the seatback relative to the seat bottom is likewise restricted. When the locking mechanism is in the unlocked state, relative rotation between the gear plate and the guide plate is permitted and, as a result, rotation of the seatback relative to the seat bottom is likewise permitted.
The locking mechanism associated with the round-recliner mechanism may include one or more pawls having a series of teeth that are in meshed engagement with teeth of the gear plate when the locking mechanism is in the locked state. The pawls may be movable between the locked state and the unlocked state by the actuation mechanism. In one configuration, the actuation mechanism may include a cam that urges the pawls into the locked state when rotated in a first direction and moves the pawls into the unlocked state when rotated in a second, opposite direction.
While the actuation mechanism adequately moves the pawls of the locking mechanism from the unlocked state to the locked state, if a force is applied to the seatback too quickly following movement of the pawls from the locked state to the unlocked state, a force may be applied to one or more of the pawls via a control ring fixed for movement with the gear plate. The force applied to the pawl(s) via the control ring may cause damage to post(s) associated with and extending from the pawl(s). Specifically, if the force exceeds a predetermined limit, the post(s) may be sheared from one or more of the pawls, thereby preventing the pawls from interacting with the control ring during operation of the round-recliner mechanism.